After the summer riots, I spent a day in my local courthouse watching the magistrate refuse almost every request for bail. The young men the police brought up from the cells might have been an unrepresentative sample of the thousands arrested. I cannot be sure. But as I looked at them penned in the dock, I could say one thing with certainty: they did not fit into any of the hand-me-down explanations for the violence rival newspapers and pundits offered the public.

Leftish columnists blamed the violence on inner-city poverty and "the cuts". The more fanciful among them held that the oppressed urban masses had risen up against a corrupt society that bailed out failed bankers and allowed MPs to line their pockets. You can say in their favour that the riots began in the ghettos of Tottenham. But that is as much as you can say. Not one reporter or police officer heard the looters chant a political slogan, and most of "the cuts" have not happened yet. In my court, the defendants were from prosperous St John's Wood. That did not mean that they were necessarily prosperous themselves. Rich and poor live side by side even in the most expensive parts of London. But one of the suspected rioters was about to go to university and did not look like a working-class hero. Another was at university studying for a law degree, no less. Funnily enough, he was the only defendant the magistrate freed on bail. Right-wing columnists insisted that the breakdown of law and order was the result of family breakdown: the grim consequence of the generation of the 1960s undermining the family and allowing single mothers to bring up children at public expense. I met one distraught father, who clearly was not absent from his son's life but had come to court to offer support. The lawyer for another pleaded that his client also had strong family values and looked after his mother and siblings.

Meanwhile David Starkey, supposedly one of our greatest historians, decided that it was all the fault of the blacks. Not one of the defendants in front of me was black. But Starkey already had an answer to such footling objections. "The whites have become black", and caught from the children of immigrants "a particular sort of violent, destructive, nihilistic, gangster culture". In Starkey's circular reasoning, even when rioters were not black, the blacks were to blame.It must be nice to be the professor and live with a mind untroubled by evidence.

The riots shocked no established commentator into changing his or her mind. You could predict the responses of left-wing and right-wing newspapers before you read them. As we have seen with so many other sudden events, no change, however violent, can shake the cocksure out of their conditioned reflexes. Whatever coin you put into the machine, the response is always the same.